If you haven't bought this bike yet, why not look for a more suitable touring bike which can take larger tires, carry a load better, and will have a better geometry for touring.

A touring bike will have more relaxed angles, and also less chance of heel strike on the rear with panniers or toe overlap on the front. no point in trying to get a bike to do something it wasn't designed to to, get one designed for the purpose in the beginning.

For the frame having plenty of "spare meat", its aluminum, most of that will be needed.